Abstract:
Due to the physical properties and welding characteristics of aluminum alloy components for railway vehicles,welding quality problems were frequently encountered during return-to-factory maintenance, which seriously affects the driving safety. Aiming at the key problem of in the weld fusion zone after weld repair of aluminum alloy components, a finite element simulation method was adopted in this work to investigate the distribution law of residual stress under different weld repair schemes. The rationality of the model was verified using thermal cycle test data. The results show that single weld repair significantly increases the residual stress at the original weld toe, and secondary weld repair does not cause it to rise further. When the low-temperature rapid thermal start process is applied for single weld repair, the residual stress at the weld toe decreases; the reduction reaches 10% in the heating initiation zone and approximately 5% in other regions. This study confirms that the adoption of the low-temperature rapid thermal start process effectively reduces the residual stress level in the weld repair zone.